Many forms of oscillators are used in electronic devices, such as personal computers, electronic instrumentation, telecommunications equipment, etc., to provide stable timing signals necessary for proper operation of the devices. In many forms, the oscillators are driven by crystals (e.g. quartz). In crystal oscillators, the crystals are trimmed such that the size and shape of the crystal determines the preferred frequency. The trimming process involves carefully cutting and polishing the crystal to vibrate at a desired frequency when operating in conjunction with an oscillator circuit. However, due to inevitable tolerances in the trimming process, crystals trimmed to operate at the same frequency do not all operate at exactly the preferred frequency. Instead, the crystals operate in a band of frequencies including the preferred frequency. Consequently, oscillators are specified with a tolerance that accounts for the statistical variation in the operational frequencies of the individual oscillators.
The preferred operating frequencies of oscillators implemented in electronic devices vary depending upon the particular application of the electronic devices. Because each application for an oscillator may require a different frequency, a distributor of crystal oscillators typically maintains a complete stock of non-programmable oscillators. The stock of oscillators are typically set for common frequencies used by electronic devices, such as computers. However, if a customer requires a custom frequency, a manufacturer of crystals must laboriously cut or plate by hand tiny electromechanical parts to obtain the required crystal characteristics for operation at the custom frequency. Furthermore, in order to provide the custom frequency, the manufacturer of the crystal oscillator may require 10 to 12 weeks to generate the custom crystal. Typically, for faster turnaround, shorter time frames incur premium charges on a sliding scale.